1. Field of the Invention
The present invention relates to pressure indicators combined with fill valves.
The motoring public is generally aware of the need to have tire properly inflated for optimum tire life and performance. Under-inflated tires (or over-inflated tires) wear more quickly and degrade the handling characteristics of a motor vehicle. The tedium of measuring the pressure in each tire causes many drivers to forego measuring the pressure in their tires and to rely on a visual inspection. However, mere visual inspection is inadequate, particularly when a car has radial tires, because a sidewall bulge is present even in properly inflated tires. The importance of properly inflated tires was acknowledged by the federal government with the passage of the TREAD Act. It mandates cars have a tire pressure management system. These are electrical in nature and it would be an advantage to have tire pressure indication that is independent of the car's electrical system to act as a backup.
It will be easier for consumers to maintain the correct pressure in their tires, if pressure indicators can be mounted onto tire valve stems and left in place when inflating the tires. Color-coding may make it easier to determine when the tire pressure is correct, especially in poorly lighted areas, or for visually impaired people.
2. Description of the Prior Art
U.S. Pat. No. 3,670,688, issued on Jun. 20, 1972, to Lewis A. Seaberg, discloses a color-coded tire pressure indicator that is mounted in a tire stem. The present invention is distinguishable, in that air can pass through it to inflate the tire.
U.S. Pat. No. 3,866,563, issued on Feb. 18, 1975, to Gary R. Bluem, discloses a color-coded tire pressure indicator that can be screwed onto a tire stem. The tire can be inflated or deflated through the device. A hollow “piston” with color-coding (or other indicia) appears to be concentric with a fill valve. The colors are viewed through concentric beads. The present invention is distinguishable in that the colors are viewed through a lens, with the aid of a mirror. Only the use of two colors is disclosed, to indicate whether the pressure is above or below a certain level. The present invention is distinguishable, in that it uses a third color to indicate that pressure is within a desirable medium range.
U.S. Pat. No. 3,990,467, issued on Nov. 9, 1976, to Neal L. Sargent, discloses a color-coded tire pressure indicator with internal screw threads at one end. The tire can be inflated or deflated through the device. A sliding pressure indicating member with color-coding appears to be concentric with a fill valve. The colors are viewed through a cylindrical window. The present invention is distinguishable in that the colors are viewed through a lens, with the aid of a mirror.
U.S. Pat. No. 4,193,295, issued on Mar. 18, 1980, to William F. Curran, and U.S. Pat. No. 4,224,214, issued on Jan. 13, 1981, to William F. Curran, disclose a color-coded tire pressure indicator that can be screwed onto a tire stem. The tire can be inflated or deflated through the device. An “axially apertured bolt” has three annular bands of different colors for indicating over inflation, proper inflation and under inflation, and appears to be concentric with a fill valve. The colors are viewed through a window in the stem housing. The present invention is distinguishable in that the colors are viewed through a lens, with the aid of a mirror. The present invention is further distinguishable, in that it includes a diaphragm to move the indicator upward as pressure increases.
U.S. Pat. No. 4,310,014, issued on Jan. 12, 1982, to James E. Parker, discloses a tire pressure indicator that is part of a tire stem, but does not disclose the combination of a lens with a mirror or the diaphragm of the present invention.
U.S. Pat. No. 5,014,643, issued on May 14, 1991, to Tien-Tsai Huang, discloses a color-coded tire pressure indicator, that allows air to escape when pressure in the tire is too high, but does not make it possible to inflate the tire when the indicator is mounted on a tire stem, as in the present invention.
U.S. Pat. No. 5,339,764, issued on Aug. 23, 1994, to Günther Singbartl, discloses a device that can use color to indicate the air pressure in a vehicle tire, but does not have means for allowing the tire to be inflated or deflated when the device is mounted on a tire stem, as in the present invention.
U.S. Pat. No. 5,365,967, issued on Nov. 22, 1994, to James C. Moore, discloses a tire pressure indicator, that provides visual indication of over inflation or under inflation, and allows air to escape when pressure in the tire is too high, but does not have means for inflating the tire when the pressure indicator is in place, as in the present invention.
U.S. Pat. No. 5,386,794, issued on Feb. 7, 1995, to Arthur J. Foss and Philip J. Milanovich, discloses a tire pressure indicator, in which air pressure is indicated by the position of a sliding marker in a sleeve attached to the side of a tire valve stem. The present invention is distinguishable, in that the pressure indicator and the fill valve are concentric.
U.S. Pat. No. 5,569,849, issued on Oct. 29, 1996, to Craig Cummings, discloses a tire stem cap that provides a visual indication when air pressure within the tire drops below a set point. The tire cannot be inflated or deflated when the device is mounted on the tire stem, as in the present invention.
U.S. Pat. No. 6,293,297, issued on Sep. 25, 2001, to Brandon Maldonado and Gene Scott, discloses an air valve housing with pressure indicator that can be screwed onto a tire stem. The tire can be inflated or deflated through the device. The pressure indicator has three colored bands for indicating adequate, marginal, and under inflated conditions. The pressure indicator is concentric with a fill valve, though an access means for enabling air pressure reduction is off to one side. The colors are viewed through a window. The present invention is distinguishable in that the colors are viewed through a lens, with the aid of a mirror. The present invention is further distinguishable, in that it includes a diaphragm to move the indicator upward as pressure increases.
U.S. Pat. No. 6,302,138, issued on Oct. 13, 2001, to Dirk Lee Sumrall, discloses tire stem valves with built in pressure regulators and optional air pressure indicators, but does not disclose the combination of a lens with a mirror or the diaphragm of the present invention.
U.S. Pat. No. 6,911,903, issued on Jun. 28, 2005, to Peter Gladstone, discloses a tire pressure indicator that can be mounted on a tire stem, which displays one color when pressure is below a set level, and another color when pressure is above that level. The tire cannot be inflated when the indicator is mounted on the tire stem, as in the present invention.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. In particular:
1. The prior art cited does not disclose the use of a free moving diaphragm with a center hole that allows air to pass through the plane of the diaphragm. The diaphragm has the advantage of being both compact and reliable. Other devices mentioned in the prior art are not as likely to provide an airtight seal under high pressure. Furthermore, non-diaphragm based indicators will likely have varying friction caused by their sealing surfaces, meaning that they will operate inconsistently and inaccurately.
2. The prior art cited does not disclose the use of a mirror to allow an indicator to be viewed from more angles. The present invention uses an angled mirror to allow the indicator to be viewed from both the top and sides. This allows the pressure indication to be viewed regardless of the degree of wheel rotation or the angle that the tire stem protrudes from the rim.